There has been known acoustic wave devices including an acoustic wave filter using an acoustic wave such as a surface acoustic wave (SAW) or a bulk acoustic wave (BAW) as a filter for wireless devices including mobile phones. The acoustic wave device requires a structure to seal and protect a functional element for exciting the acoustic wave. For example, Japanese Patent Application Publication No. 2005-514846 discloses connecting an acoustic wave chip having an acoustic wave device formed therein to a support substrate by solder and hermetically sealing it by a resin.
The conventional acoustic wave device has been fabricated by separately performing a process of connecting a signal terminal on the acoustic wave chip to a terminal on a support substrate and a process of hermetically sealing the acoustic wave chip. Thus, the number of fabrication processes increases, and the production cost thus increases.